This invention relates to the field of automatic test equipment (ATE), and more particularly to the automatic integration of one or more of a variety of ATE instrument resources, notably IEEE-488 based devices such as computers, counters, power supplies, meters, printers, etc., into a system which is thereby tailored for a particular test procedure or series of procedures.
Traditionally, the large tightly integrated automatic test system has been used to increase the productivity of high-volume/low-variety testing-dominant operations and was built by a system integrator who combined various IEEE-488 resources via software and hardware to satisfy a particular user. Such a system usually had a markup of two to eight times the cost of the resources and was difficult to alter in response to changing user needs such as replacement of obsolete resources and test requirement updates.
Heretofore, it has been the practice for the user of an IEEE-488 based test system of the type having a controller that communicates via an IEEE-488 bus with individual test resources or instruments to manually set address switches in the controller to initilize the system. This presupposes that the address of each resource is known, and requires considerable down-time of the system to effect a new test configuration. U.S. Pat. No. 3,764,995 shows a programmable test system wherein automatic switching is accomplished by a relay matrix to configure a system having predetermined resources of known addresses as preexisting components of the system. While that approach allows some flexibility it is limited to the resources and configurations previously established by the relay matrix.
Attempts to apply ATE system technology to repair operations, for example of specialized avionics systems, have met with only limited success because the workload is typically low-volume/high-variety in nature and human intervention is dominant. The resulting set-up/tear-down penalties and human intervention aspects of the testing have rendered the test systems idle for inordinate periods of time. Accordingly, it would be desirable to have an automatically reconfigurable, on-line ATE system that includes an IEEE-488 based information distribution system that will make assembly and reassembly automatic test systems as easy and inexpensive as manual test systems are now, with all the advantages previously reserved to application to high volume production testing situations.